Method of nitrating organic substances



Patented Nov. 21 i933 TES METHOD OF NITRATDW G ORGANIC SUBSTANCE S Arthur Hough, Passaic, N. J.

No Drawing.

Application December 3, 1928 Serial No. 323,584

6 Claims.

My invention relates to the nitration of organic substances, and more particularly to diethylene glycol having the composition,

CH2OH.CH2.O.CH2CH2OI-I to form the di-m'trate .CH2(NO3) .CH2 .O.CH2.CH2(NO3) and has for its objects the safe nitration of the di-ethylene glycol in a highly efficient manner, resulting in high yield, great stability of the product, quick separation from the spent acids, and a highly satisfactory condition of such spent -acid well suited to dem'tration in the tower provided for such purpose.

Di-ethylene glycol dinitrate is a compound possessing very valuable properties readily employed in the explosives industry. Dissolved in tri-nitroglycerine the freezing point of the resulting mixture is very considerably below that of the pure nitroglycerine, and when added to trinitroglycerine in the proportions of about 8 parts by weight of di-ethylene glycol dinitrate and 92 parts of tri-nitro glycerine, the freezing point is not only depressed but the actual power developed from this mixture is considerably greater than that derivable from an equal weight of pure tri-nitro glycerine. This of course can be explained by the mixture having an exactly balanced composition, the products of explosion being CO2.H2O and N. whereas, in the case of tri-nitro glycerine alone there results from the explosion free oxygen, and consequently lower power. Another valuable feature of such a mixture is the safety, it being far less sensitive to shocks and friction than pure tri-nitro glycerine, but when exploded by a fulminate detonator, the velocity of detonation exceeds by far that of nitro-glycerine alone, and the mixture is more sensitive to the fulminate cap than is nitroglycerine alone. It hence is an excellent blasting (detonating) explosive.

Di-ethylene glycol dinitrate may be mixed with ethylene glycol dinitrate, in which it is soluble in all proportions, making an explosive having a very low freezing temperature, but the actual explosive value of the mixture is somewhat less than that of the pure ethylene glycol di-nitrate. The addition of the diethylene glycol di-nitrate however to either of the above mentioned explosives imparts to the mixture great solvent property for nitro-cellulose of the intermediate nitrogen content varietycontaining eleven to twelve per cent of nitrogen. The solution being brought about in the cold. This is a very valuable factor in the manufacture of gelatine explosives.

Di-ethylene glycol di-nitrate is the ideal component in the preparation of smokeless powder propellants. Such explosives can be produced by colloiding, by means of the di-ethylene glycol di-nitrate, a suitable grade of nitro-cellulose, and the extremely small amount of volatile solvent re quired, makes it possible to manufacture the finished propellant in a fraction of the time now required to evaporate the solvent from the propellants of the compositions now commonly used. This makes a highly useful explosive since it has a low temperature of combustion and produces a large volume of gases.

In the past, all attempts to nitrate di-ethylene glycol by ordinary methods have resulted in failure, for particulars relative to this I refer to Rinkenbach, Journal of Industrial & Engineering Chemistry, August 1927, page 925. By the process described in said article very low yields will be obtained and actual decomposition will result during the process. Said process also would be highly dangerous. The method given in said article followed very closely that of ordinary nitration processes, in which the ratio of sulphuric acid to nitric acid in the original nitrating mixture is too high to give satisfactory yields.

I have discovered that the correct way to nitrate diethylene glycol is to employ an acid mixture in which the nitric acid content of the nitrating acid mixture bears a much higher ratio to the sulphuric acid than is ordinarily employed in the nitration art, and the total acidity of the nitrating mixture must be moderate, or in other words the water content of the acid mixture must be considerably higher than has usually been considered necessary in processes heretofore commercially used for nitrating similar ma terials.

The following are some typical examples of acid nitrating mixtures, that give good results, viz.:

:::::::::: it ti t m 1 All of the above acid mixtures give yields of di-ethylene glycol dinitrate closely approaching the theoretical, with a rapid and clean separa tion from the spent acids.

. Tfie ratio of I-INOs to H2SO4 in A is 0.9 to 1 and in F this ratio is about 1.227 to 1. In the other examples B, C, D and the ratio is intermediate these' fig'ures. lhe last mentioned'acid mixture gives'theb'est'yieldl To conduct a nitration it is only necessaryto cool the acid mixture to preferably 10 C. and... run in the di-ethylene glycol with good agita tion, maintaining a temperature of. about 10? 0.1. to 15 C. An allowance of from 5 to 10% excess-1 of nitric acid in the nitrating mixture over and above the theoretical amount required for the nitration is sufiicient. The product-of nitration, on standing for a few minutes will rise tothe surface of the acids, when it may be decanted ofi and washed with water and neutralized 'with a little sodium-carbonate solution or any suitable alkali until it'stands the heat test usually applied to nitrated products. A last Wash with warm water will stabilize the product to that extent that it will stand the IQ starch paper heattest "for .an. hour orinore.

Having thus, described my invention, what I desire to obtain by United States Letters Patent 1. The method of nitrating diethylene glycol by adding it alone to an acid mixture consisting of sulphuric acid, nitric acid and water, the sulphuric and the nitric being in about equal proportions and the water content initially being over 5%,oi the whole, but being only a minor fraction of the amount of nitric acid, substantially as described.

2. The method of nitrating a mixture containing diethylene glycol and ethylene glycol by adding such mixture to an acid mixture consisting of about 1 part of sulphuric acid, about 0.9 to 1.227

parts of nitric acid and about 5.9 to 7.33% of water...

3.-- Almod of nitrating diethylene glycoliwhich comprisesadding same we mixture ofnitric acid,sulphuric acid and Water in which the nitric acid to sulphuric acid ratio is within the range 0.931 to 1.22711 and in which the water content is above 5 tlieitemperature being kept at not substantially above 15 C.

4. A. mode. of nitrating mixtures containing a liquid' polyatomic alcohol and diethylene glycol which comprises adding the same to a mixture of nitric acid, sulphuric acid and water in which the nitric acid to sulphuric acid ratio is within the substantially above 15C.

5. A mode of nitrating diethylene glycol w e comprises adding same toa mixture of nitric acid, sulphuric acid andwater-in which the-nitric acid to sulphuric acid ratio is within therange 0.9:1

to l.227:l and in which the water'content is at least 5.9%, the amount ofnitric acid being'about 5 to 10% in excess of the theoretical, the tempera,

ture being kept at not substantially .above15" C.

6. A mode of nitrating diethylene-glycol which temperature being kept at not substantially above.

ARTHUR .HOUGH. 

